Multi-lumen catheter with attachable hub

ABSTRACT

The present invention is a multi-lumen catheter assembly having an selectively attachable hub including a multi-lumen catheter tube that has a proximal portion and a distal portion and a hub assembly that has a proximal portion and a distal portion, whereby the distal portion of the catheter tube is selectively attachable to the proximal portion of the hub assembly after subcutaneous insertion of the proximal portion of the catheter tube into a patient.

FIELD OF THE INVENTION

[0001] The present invention relates generally to medicalinstrumentation and more specifically to a multi-lumen catheter with aselectively attachable hub assembly that allows the catheter tip to bepositioned accurately prior to subcutaneous tunneling.

BACKGROUND OF THE INVENTION

[0002] Catheters, generally, are hollow, flexible tubes for insertioninto a body cavity, duct, or vessel to allow the passage of fluids ordistend a passageway. Catheters are often used for temporary orlong-term dialysis treatment. Dialysis treatment provides for blood tobe withdrawn from the patient, purified, and then returned to thepatient. Thus, in dialysis treatment, catheters are used to allowpassage of a patient's blood into and out of the patient's body. Foroptimal performance during dialysis treatment, the catheter tips, bothin-flow and outflow, should be placed in close proximity to the heart.Typically, medical personnel use either a double lumen catheter or twosingle lumen catheters. Both types, however, present certaindeficiencies.

[0003] While double lumen catheters (e.g., U.S. Pat. No. 4,895,561)allow for a single venous insertion of the catheter into the desiredvein, double lumen catheters typically do not provide for accuracy ofcatheter tip placement. Due to differences among patients, optimal tipposition varies from patient to patient. Non-optimal tip position maysignificantly lower flow values, resulting in less effective dialysistreatment. For current double lumen catheters, a physician must make anestimate regarding the appropriate catheter tube length prior tobeginning the procedure of catheterization. Then, a subcutaneous tunnelis made from the preferred end position of the hub assembly, namely,away from the neck of the patient in order to allow for more convenientaccess to the dialysis treatment equipment. The double lumen cathetertube is then tunneled forwardly into the patient's vein. The initialestimate and subsequent forward tunneling may result in less thanoptimal tip placement.

[0004] With the use of two independent catheters (e.g., U.S. Pat. Nos.5,776,111 and 5,624,413) the problem of tip placement is addressed. Thehub assembly of each catheter is removable from the tube and tip portionof the catheter, thereby allowing the catheter tip to be placed directlyinto the vein and advanced into the desired position. Then, the proximalend of the catheter can be reversed tunneled and trimmed to a desiredlength. Thereafter, the hub assembly is attached. Deficiencies, however,exist in this method of catheterization as well. One problem associatedwith this method is that this method requires two separate venousinsertions, namely, two tunnels and two of each accessory instrumentused for the procedure. Therefore, there is increased surgical timerequired to place two catheters, there are two wound entry sites whichdoubles the risk of post-surgical infection, and the two catheterstogether are significantly larger in diameter than one double lumencatheter.

SUMMARY OF THE INVENTION

[0005] The present invention is a double lumen catheter with aselectively detachable hub assembly that allows the catheter tip to bepositioned accurately within a patient's vein prior to subcutaneoustunneling. The distal end of the catheter tube is not permanentlyattached to the hub assembly. Therefore, the catheter may be reversetunneled after the tips have been positioned.

[0006] The hub assembly includes at least two cannulae that coordinateand correspond to the at least two lumen at the distal end of thecatheter tube. Once the hub assembly is connected to the catheter tubeso as to provide fluid communication therebetween, preferably, aconnection cover and a malleable compression sleeve are secured intoplace. Preferably, the connection cover is threaded to mate with athreaded connection on the hub assembly. The connection cover and thecompression sleeve together create force to prevent inadvertentseparation of the catheter tube from the hub assembly.

[0007] These and other aspects of the present invention as disclosedherein will become apparent to those skilled in the art after a readingof the following description of the preferred embodiments and drawings.The description and drawings are for the purpose of describing apreferred embodiment of the invention and are not intended to limit thepresent invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008]FIG. 1 is an exploded, perspective view of a multi-lumen catheterassembly of the present invention.

[0009]FIG. 2 is an enlarged, exploded, perspective view of a hubassembly of the multi-lumen catheter assembly of the present invention,including a first cross-sectional view of the hub body.

[0010]FIG. 3 is an enlarged, exploded, perspective view of the hubassembly and distal portion of a catheter tube of the present invention,including the first cross-sectional view of the hub body.

[0011]FIG. 4 is a first cross-sectional view of the catheter tube of themulti-lumen catheter of the present invention.

[0012]FIG. 5 is an enlarged perspective view of the catheter tube of thepresent invention.

[0013]FIG. 6 is a perspective view of an assembled multi-lumen catheterassembly of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0014] As shown in the Figures, the present invention is a multi-lumencatheter assembly 10 having a selectively attachable hub assembly 20. Asshown in FIG. 1, a multi-lumen catheter tube 12 is formed with aproximal portion 12 a and a distal portion 12 b. The distal portion 12 bof the catheter tube 12 is selectively attachable to the proximalportion 20 a of the hub assembly 20. In this manner, the hub assembly 20may be attached to the catheter tube 12 after insertion of the proximalportion 12 a of the catheter tube, including tips 14 and 16, into apatient.

[0015] As illustrated in FIG. 2, preferably, the hub assembly 20 has afirst cannula 22 and a second cannula 24. Each of the cannulae has aproximal portion 22 a and 24 a, respectively, and a distal portion 22 band 24 b, respectively. Further, each cannulae 22 and 24 has anassociated extension tube, 26 and 28 respectively. Each of the extensiontubes 26 and 28 has a proximal portion 26 a and 28 a, respectively, anda distal portion 26 b and 28 b, respectively. Each of the extensiontubes 26 and 28 are in fluid communication with the first cannula 22 andsecond cannula 24, respectively, through appropriate connection ofrespective proximal and distal portions, namely connection of thecannulae distal portions 22 b and 24 b with extension tube proximalportions 26 a and 28 a, respectively. While the drawings depict the hubassembly with two cannulae, any appropriate configuration and number ofcannulae should be considered within the scope of the present invention.

[0016] As shown in FIG. 2, preferably, the hub body 21 is formed tomaintain the angle A between the first extension tube 26 and the secondextension tube 28 at about 15 degrees. This angle is preferred basedupon the necessity for connecting the catheter assembly 10 to the fluidconveying device, e.g., dialysis equipment.

[0017] Returning to FIG. 1, the hub assembly 20 further includes a firstconnector 30 and a second connector 32. The connectors 30, 32 may beluer fittings, as are known in the art. The first connector 30 issecurely attached to the distal portion of the first extension tube 26 band the second connector 32 is securely attached to the distal portionof the second extension tube 28 b. Each of the connectors 30, 32preferably is attachable to a fluid conveying device (not shown), suchas dialysis equipment, as is known in the art. Thus, the respectivecannulae 22 and 24 are in fluid communication with extension tubes 26and 28, respectively. Therefore, the cannulae 22, 24 provide forrespective in-flow and out-flow operation of the fluid conveying device.

[0018] Each extension tube 26 and 28 has a clamp, 42 and 44,respectively, for clamping the extension tubes 26 and 28 when thecatheter assembly 10 is not connected to a fluid conveying device.

[0019] The hub body 21 has two suture wings 38 and 40, which can be usedto suture the catheter assembly 10 to the patient to maintain theposition of the catheter assembly 10 after insertion into the patient.

[0020] As shown in FIG. 3, the hub assembly 20 preferably is formed suchthat each proximal end of the cannulae 22 a and 24 a has a generallyD-shaped cross-section. Preferably, the distal portion of each of thecannulae 22 b and 24 b has a generally O-shaped cross-section. As such,preferably, the proximal portions 26 a and 28 a of each of the extensiontubes 26 and 28 a have a generally O-shaped cross-section and areconfigured to receive the distal portions 22 b and 24 b of therespective first and second cannulae 22 and 24. The shape andcross-section configuration of the cannulae 22, 24 the extension tubes26, 28 and the lumens 13, 17 of the catheter tube 12, may be varied,and, thus, the scope of the present invention should not be limited tothe above-described preferred configuration.

[0021] Preferably, a hub body 21 is formed around the proximal portionsof each of the extension tubes and the distal portions of each of thecannulae. As illustrated in FIG. 2, the hub body 21 provides forprotection against disconnection of the several connections betweencannulae 22, 24 and extension tubes 26, 28. Further, the hub body 21provides a structure for connection with the catheter tube 12. Morespecifically, hub body 21 has a proximal portion 21 a and a distalportion 21 b. As previously mentioned, the hub body 21 is selectivelyattachable to the distal portion 12 b of the catheter tube 12 so as toprovide fluid communication between the respective cannulae 22 and 24(via proximal portions of the cannula 22 a and 24 a) with the lumens 13and 17, respectively, of the catheter tube 12, which is discussed inmore detail below.

[0022] As shown in FIG. 5, the catheter tube 12 has a first lumen 13 andsecond lumen 17. Each of the first and second lumen 13, 17 has agenerally D-shaped cross-section. A longitudinally extending septum 15defines each lumen 13, 17 up through the distal portion of the cathetertube 12 b, as shown in FIG. 4. Therefore, each lumen 13, 17 connects toa respective cannula 22, 24 for fluid communication therewith.

[0023] Preferably, each lumen 13, 17 of the distal portion 12 b of thecatheter tube 12, and the proximal ends 22 a and 24 a of the cannulae 22and 24 are correspondingly marked by an indicator, such as a color, toensure proper matched correspondence upon connection. To further ensurematched correspondence, preferably tips 14, 16, extension tubes 26, 28and connectors 30, 32 follow the same marking pattern. Thus, forexample, tip 14, the lumen 13, cannula 22, extension tube 26, andconnector 30 are marked with a first indicator (e.g., the color blue),while tip 16, lumen 17, cannula 24, extension tube 28, and connector 32are marked with a second indicator (e.g., the color red). Thus, thefirst indicator is associated with one of the lumens and a secondindicator is associated with the other lumen, such that the firstindicator and the second indicator define a correspondence between thatlumen and an associated cannula, extension tube, and connector. Whilethe indicator may be a visual indicator such as color, a selectivelyattachable multi-lumen catheter with any indicator, visual, tactile, orotherwise, should be considered within the scope of the invention.

[0024] As described above, the invention is described with a preferredembodiment containing two cannulae and a dual-lumen catheter. Thepresent invention should not be limited, however, to this preferredembodiment and other appropriate configurations should be consideredwithin the scope of the present invention. For example, the cathetertube and corresponding cannulae may be a series of concentric tubes ofvarying diameter. Alternatively, the assembly 10 may provide a similarconfiguration to that described hereinabove with three (or more)cannulae and a triple (or more) lumen catheter tube. The preferredembodiment, however, includes two cannulae with a dual-lumen cathetertube.

[0025] Preferably, as shown in FIG. 3, the connection between theproximal portions 22 a, 24 a of the cannulae 22, 24 and the lumens 13and 17 at the distal portion 12 b of the catheter tube 12 is anoverlapping fitted connection. However, any other appropriate fasteningmeans, such as detents may be used.

[0026] Returning to FIG. 1, an example of a preferred connection betweenhub body 21 and catheter tube 12 is shown, which includes a connectioncover 34 having a proximal portion 34 a and a distal portion 34 b.Connection cover 34 should fit axially about the distal portion 12 b ofthe catheter tube 12. The distal end 34 b of the connection cover 34 isappropriately threaded such that the connection cover 34 is selectivelyattachable to the threaded portion 21 a of the hub body 21 such that thecatheter tube 12 is securely attached to the hub assembly 20. Forexample, as illustrated in FIG. 1, the connection cover 34 may includefemale threads to selectively receive the male threads 21 a formed onhub body 21.

[0027] Preferably, the present invention also includes a compressionsleeve 36 that fits axially about the distal portion 12 b of thecatheter tube 12 as well as fitting axially about the combined proximalportions 22 a and 24 a of the first and second cannulae 22 and 24.Compression sleeve 36 preferably is formed of malleable material so asto provide further compression about the connection between the cannulae22 and 24 with the multi-lumen catheter tube 12. The connection cover 34and the compression sleeve 36 together create force to preventinadvertent separation of the catheter tube 12 from the hub body 21after insertion of the catheter tube 12 into a patient.

[0028]FIG. 6 shows the catheter assembly 10 of the present inventionwith the hub assembly 20 attached to the catheter tube 12.

[0029] A preferred method for inserting into a patient the catheterassembly 10 of the present invention requires the following: amulti-lumen catheter tube 12 with, preferably, tapered silicone tips 14,16, and, as are known in the art, an introducer needle, multiple tearaway sheath dilator introducers, J-flex guidewires, trocars, lock rightadapters with clamps, injection caps, a scalpel, sutures, and adhesivewound dressing. Additionally, the physician should have access toscissors, forceps, needles dish, syringes and gauzes.

[0030] A preferred method for insertion of the catheter of the presentinvention into a patient's jugular vein begins with placing the patientin a position with the patient's head turned to the opposite side ofwhere the jugular vein is to be cannulated. The anatomical landmark forproper insertion is defined by the triangle formed by the lateral edgeof the sternal head, the medial edge of the clavicular head of thesternocleidomastoid muscle, and the upper edge of the clavicle.

[0031] The patient's neck and a portion of the patient's thorax beneaththe clavicle, preferably at least about 20 centimeters (cm), should beappropriately prepared for incision. Thereafter, the patient should bedraped and local anesthetic should be administered.

[0032] Preferably, a skin wheel should be created, taking care toinfiltrate the subcutaneous tissue for about 2 to 3 cm. Next, preferablywith an 18-gauge needle attached to a syringe, the physician shouldidentify the internal jugular vein by aspiration and then proceed at anangle while continuing to aspirate with the syringe. Once the internaljugular vein has been located, the preferred method includes detachingthe syringe while leaving the needle in place. The needle opening shouldthen be occlused and thereafter the J-flex guidewire should beintroduced through the needle and into the internal jugular vein. Theguidewire should pass without resistance into the exact position. Theneedle should be removed, thus leaving the guidewire in place. Theguidewire should rest at the junction of the superior vena cava and theright atrium. Appropriate guidewire placement can be confirmed withfluoroscopy.

[0033] Next, with a scalpel, the physician should make an incision inthe skin that is wide enough for the catheter tube 12 to pass. Atearaway sheath dilator may be introduced over the guidewire and intothe vein far enough to dilate the vessel. After expanding the vein wall,the guidewire may be removed while occluding the dilator opening. Atrocar should be screwed onto the catheter tube 12 by turning the trocarclockwise, but not the catheter tube 12. Turning the catheter tube 12may cause it to kink. The dilator may be removed, leaving the tearawaysheath in place to introduce the catheter tube 12, again being carefulto occlude the sheath opening. As the catheter tube 12 is fed into thesheath the tearaway sheath may be torn away. Care should be taken thatthe catheter tube 12 does not back out of the vessel.

[0034] Air embolus is avoided by the patient's positioning describedabove, and also by asking the patient to inhale deeply and then holdtheir breath. At this point, fluoroscopy should be performed to confirmcatheter tube 12 placement. The tip 14 of the venus catheter shouldreach the opening of the right atrium and the tip 16 of the arterialcatheter should be approximately 4 cm higher. As described above, properpositioning is important. Positioning, as described, is believed toprevent blood recirculation during hemodialysis.

[0035] Next, a tunnel, of about 8 to 10 cm, should be created in acaudal and internal direction by means of the tunneler, which may beshaped to physician preference. The catheter tube 12 should be gentlypulled through the tunnel until the loop at the original puncture siteis gone. When correctly inserted, the catheter tube 12 should rest overthe clavicle. Care should be taken to avoid excessive force, as this maycause the catheter tube 12 to separate from the tunnel. Preferably, themethod includes surveying this area to ensure there are no kinks in thecatheter tube 12 and there is a smooth turn.

[0036] Next, while pinching the distal portion 12 b of the catheter tube12, the hub assembly 20 is attached to the catheter tube 12. Theconnector 34 is backfit over the catheter tube 12. Next, the compressionsleeve 36 is backfit over the catheter tube 12. The proximal portions 22a, 24 a of cannulae 22, 24 are inserted into lumens 13 and 17,respectively, creating a friction fit. Preferably, the cannulae 22, 24,or the corresponding extension tubes 26, 28 or the correspondingconnectors 30, 32 are marked so that the cannulae 22, 24 are insertedinto the correct lumens 13, 17.

[0037] After backbiting the connector cover 34 and the compressionsleeve 36 over the catheter tube 12, the compression sleeve 36 is slidinto a position that is approximately adjacent to the threaded portion21 a of the hub body 21. Finally, the connector cover 34 is attached tothe hub body 21 by turning the connector cover 34 so that the femalethreaded portion of the connector cover 34 receives the male threadedportion 21 a of the hub body 21 thereby creating a secure attachment ofthe hub assembly 20 to the catheter tube 12. Clamps 42, 44 may be usedwith extension tubes 26, 28.

[0038] The extension tubes 26, 28 should be filled with 3 to 4 cc of5000 units of heperinized saline, clamped, and attached with theinjection cap. X-rays should again be performed to reconfirm placement.The small incision is closed with sutures. The patient is now ready fordialysis.

[0039] Preferably, the catheter tube 12 is formed with radioopaquesilicone, to facilitate visualization under fluoroscopy.

[0040] Although specific embodiments of the present invention have beenillustrated and described in detail, it is to be expressly understoodthat the invention is not limited thereto. The above detaileddescription of the embodiment is provided for example only and shouldnot be construed as constituting any limitation of the invention.Modifications will be obvious to those skilled in the art, and allmodifications that do not depart from the spirit of the invention areintended to be included within the scope of the appended claims.

What is claimed is:
 1. A multi-lumen catheter assembly having anselectively attachable hub, comprising: a multi-lumen catheter tubehaving a proximal portion and a distal portion; and a hub assemblyhaving a proximal portion and a distal portion, wherein the distalportion of the catheter tube is selectively attachable to the proximalportion of the hub assembly after subcutaneous insertion of the proximalportion of the catheter tube into a patient.
 2. The multi-lumen catheterassembly of claim 1, wherein the catheter tube has a first lumen and asecond lumen, and wherein the hub assembly is further comprised of: afirst cannula and a second cannula, wherein each of the cannulae has aproximal portion and a distal portion, the proximal portion of the firstcannula being connectable with the first lumen of the catheter tube, andthe proximal portion of the second cannula being connectable with thesecond lumen of the catheter tube, to provide for fluid communicationtherebetween; a first extension tube and a second extension tube,wherein each of the extension tubes has a proximal portion and a distalportion, and wherein the proximal portion of the first extension tube isconnectable with the distal portion of the first cannula, and theproximal portion of the second extension tube is connectable with thedistal portion of the second cannula, to provide fluid communicationtherebetween; and a first connector and a second connector, the firstconnector being securely attached to the distal portion of the firstextension tube and the second connector being securely attached to thedistal portion of the second extension tube, wherein each of theconnectors are attachable to a fluid conveying device to provide fluidflow between the hub assembly and the catheter tube.
 3. The multi-lumencatheter assembly of claim 2, wherein the proximal portion of each ofthe first and second cannulae have a generally D-shaped cross-sectionand the distal portion of each of the first and second cannulae have agenerally O-shaped cross-section.
 4. The multi-lumen catheter assemblyof claim 3, wherein the proximal portions of each of the extension tubeshave a generally O-shaped cross-section and are configured to receivethe distal portion of a respective cannulae.
 5. The hub assembly ofclaim 2 further comprising: a hub body formed about the connectionbetween the proximal portion of each extension tube with the distalportion of each cannula.
 6. The multi-lumen catheter assembly of claim5, further comprising: a connection cover having a proximal portion anda distal portion, wherein the cover fits axially about the distalportion of the catheter tube; and a compression sleeve, the compressionsleeve fitting axially about the distal portion of the catheter tube andthe proximal portion of the first and second cannulae; wherein thedistal end of the cover is selectively connectable to the hub assembly.7. The multi-lumen catheter assembly of claim 6, wherein the hub bodyhas a proximal portion and a distal portion, the proximal portion of thehub body being selectively attachable to the distal portion of theconnection cover, such that the catheter tube is securely attached tothe hub assembly.
 8. The multi-lumen catheter of claim 2, wherein theangle between the first cannula and the second cannula is about 15degrees.
 9. The multi-lumen catheter of claim 1, wherein the proximalportion of the catheter tube further comprises a first and second lumen,each of the first and second lumens having a generally D-shapedcross-section, wherein each of the first and second lumens transitiontoward the distal portion of the catheter tube into a single lumenhaving a longitudinally extending septum.
 10. The multi-lumen catheterof claim 2, wherein a first indicator is associated with a first lumen,the first cannula, and the first connector; and a second indicator isassociated with a second lumen, the second cannula, and the secondconnector; such that the first indicator and the second indicator definea matching correspondence between the lumens, the cannulae, and theconnectors.
 11. A multi-lumen catheter assembly having a selectivelyattachable hub, comprising: a) a multi-lumen catheter tube having aproximal portion and a distal portion and a first lumen and a secondlumen; and b) a hub assembly, the hub assembly further comprising: i) afirst cannula and a second cannula, wherein each of the cannulae has aproximal portion of D-shaped cross-section and a distal portion ofO-shaped cross-section, the proximal portion of the first cannula beingconnectable with the first lumen of the catheter tube, and the proximalportion of the second cannula being connectable with the second lumen ofthe catheter tube, to provide for fluid communication therebetween; ii)a first extension tube and a second extension tube, wherein each of theextension tubes has a proximal portion and a distal portion, and whereinthe proximal portion of the first extension tube has an O-shapedcross-section and is connectable with the distal portion of the firstcannula, and the proximal portion of the second extension tube has anO-shaped cross-section and is connectable with the distal portion of thesecond cannula, to provide fluid communication therebetween; iii) afirst connector and a second connector, the first connector beingsecurely attached to the distal portion of the first extension tube andthe second connector being securely attached to the distal portion ofthe second extension tube; and iv) a hub body having a proximal portionand a distal portion, the hub body being formed about the connectionbetween the proximal portions of each of the first and second extensiontubes with the distal portions of each of the first and second cannulae,respectively; v) a first indicator is associated with a first lumen, thefirst cannula, and the first connector; and a second indicator isassociated with a second lumen, the second cannula, and the secondconnector, such that the first indicator and the second indicator definea matching correspondence between the lumens, the cannulae, and theconnectors; c) a connection cover having a proximal portion and a distalportion, wherein the cover fits axially about the distal portion of thecatheter tube; and d) a compression sleeve, the compression sleevefitting axially about the distal portion of the catheter tube and theproximal portion of the first and second cannulae; wherein the proximalportion of the hub body being selectively attachable to the distalportion of the connection cover, such that the catheter tube isselectively attachable to the hub assembly after insertion of theproximal portion of the catheter tube into a patient.